Chapter 12
Digestive System
Chapter Objectives
Upon completion of this chapter the participant will be able to:
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List the functions of the six major organs of the digestive system.
Label the organs of the digestive system on a diagram.
Discuss the functions of the accessory organs of the digestive system.
Label the accessory organs of the digestive system on a diagram.
Discuss the normal process of digestion.
Analyze, define, spell and pronounce the medical terms of the digestive system.
Successfully complete the review exercises at the end of the chapter.
Digestion is the process of breaking down complex foods into simple nutrients that can
be used by the body. This process occurs in the body’s digestive system. Essentially
the digestive system is a long tube, plus four accessory organs that are medically
referred to as the gastrointestinal tract or alimentary canal (aliment/o). The
digestive system extends from the mouth to the anus. As food is eaten a process of
wavelike motions peristalsis moves the food through the system.
Functions of the Digestive System
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Take food into the body
Break food down into simpler substances
Absorb nutrients from the digested food
Eliminate solid wastes produced during digestion
Structures of the Digestive System
 Oral cavity (or/o) or mouth (stomat/o) and all its structures. It is composed of
the lips (cheil/o, labi/o), the cheeks (bucc/o), the palate or roof of the mouth
(palat/o), the uvula (uvul/o), the tongue (gloss/o, lingu/o), the teeth (dent/i,
dent/o, odont/o) the gums (gingiv/o), and the salivary glands.
 Pharynx (pharyng/o) is the passageway for food as it travels to the stomach.
 Esophagus (esophag/o) connects the pharynx to the stomach. At the end of
the esophagus there is a one-way sphincter called the cardiac sphincter that
opens into the stomach and lets the food in. The esophagus is also known as
the gullet.
 Stomach (gastr/o) is a sac-like organ where food is received and the process of
digestion carried out. It contains many folds of tissue that contain openings for
digestive juices to be dumped onto the food to carry out this digestive process.
At the end of the stomach is another sphincter which allows the food to move out
of the stomach. This sphincter is referred to as the pyloric sphincter (pylor/o).
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 Small intestine (enter/o) which is often referred to as the small bowel. It is
coiled in the abdominal cavity and is about 21 feet long. It consists of three
distinct sections: duodenum (duoden/o, duoden/i), jejunum (jejun/o) and the
ileum (ile/o).
 Large intestine which is often referred to as the large bowel and consists of
cecum (cec/o), colon (col/o, colon/o), sigmoid (sigmoid/o), rectum (rect/o)
and anus (an/o). The anus and rectum together have (proct/o) as their root.
Esophagus
Liver
Stomach
Pancreas
Large intestine (Transverse colon)
x
Small intestine
Large intestine
(Ascending colon)
Large intestine (Descending Colon)
Appendix
Anus
Accessory Organs of Digestion
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Salivary glands are a series of glands found in the mouth that are responsible
for secreting saliva the first enzyme to begin digestion of food.
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Liver. (hepat/o)The liver is the largest organ in the body, weighing about four
pounds. It is located in the right upper quadrant of the abdomen and is divided
into a right and left lobe. It is responsible for: production of bile that will digest
fats, breakdown and storage of carbohydrates, fats and proteins, storage of
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sugar as glycogen, storage of vitamins, detoxification of harmful substances and
production of factors responsible for clotting of blood. Cirrhosis is a common
liver disease where there is progressive degeneration of the tissue.
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Biliary Tract. The biliary tract includes the gall bladder, the hepatic ducts,
cystic ducts and common bile duct. Bile leaves the liver through the hepatic
duct and goes into the cystic duct which takes it to the gall bladder (cholecyst/o)
for storage. When bile is needed in the small intestine to digest fats it travels to
the intestine through the common bile duct.
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Pancreas. The pancreas is a fish-shaped organ that lies behind the stomach. It
secretes an enzyme called pancreatic juice which is released into the
pancreatic duct and then into the small intestine to aid in digestion. The
pancreas is also part of the endocrine system in that it contains cells that release
a hormone, insulin, responsible for the absorption of sugar.
Cystic duct
Gall Bladder
Hepatic duct
Liver
Common
bile duct
Pancreas
Small intestine
Peritoneum
The components of the digestive system are encased in a membrane lining called the
peritoneum. This membranous lining covers all the organs of the abdomen and pelvis
located below the diaphragm. The peritoneum consists of two layers, the parietal and
visceral and the space between the layers is referred to as the peritoneal cavity. This
cavity is filled with a fluid called peritoneal fluid that prevents the layers from rubbing
together.
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Diseases of the Digestive System
Since the digestive system extends a long distance there are a variety of health
problems that one can encounter and also a variety of procedures that can be used to
diagnose these problems. A number of the procedures involve the use of a scope to
look into a particular part of the system: e.g. gastroscopy, sigmoidoscopy,
colonoscopy. During any of these procedures the physician has the opportunity of
taking a small sample of tissue (biopsy) as well as visually looking at the tissue. One
common progressive degenerative condition of the liver is cirrhosis which is often
linked to an excessive intake of alcohol over a long period of time.
One of the most common health problems of the digestive system is inflammation (-itis)
and it can affect all areas and all parts of the system: gastritis, hepatitis, pancreatitis,
colitis. When this happens the patient will complain of pain and often will need to be
placed on a special diet and/or require surgical intervention.
Word Parts for the Digestive System
Roots
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an/o
append/o, appendic/o
bil/i
bucc/o
cec/o
cheil/o, labi/o
chol/e
cholangi/o
cholecyst/o
choledoch/o
col/o, colon/o
cyst/o
dent/o, dent/i odont/o
divert/i
duoden/o, duoden/i
enter/o
esophag/o
gastr/o
gingiv/o
gloss/o, lingu/o
hepat/o
ile/o
jejun/o
lapar/o
lith/o
orex/i
or/o, stomat/o
palat/o
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anus
appendix
bile
cheek
cecum
lips
bile, gall
bile duct; bile vessel
gall bladder
common bile duct
colon, large intestine
cyst, sac, bladder
tooth, teeth
turning aside
duodenum
small intestine
esophagus
stomach
gums
tongue
liver
ileum
jejunum
abdomen
stone
appetite
mouth
palate
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pancreat/o
peps/o, peps/i
peritone/o
pharyng/o
proct/o
pylor/o
rect/o
sial/o
sialaden/o
sigmoid/o
steat/o, lip/o, adip/o
uvul/o
viscer/o
pancreas
digest, digestion
peritoneum
pharynx, throat
rectum and anus together
pylorus
rectum
saliva
salivary gland
sigmoid colon
fat
little grape, uvula
internal organs
Suffixes
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-chalasia
-grade
-emesis
-lithiasis
-phagia
-plakia
-pepsia
-pexy
-stalsis
relaxation
to step up, to go
vomiting
presence of stones
eating, swallowing
patches
digestion
surgical fixation
contraction
Prefixes
 anti endo meta-
against
within
change
Term Analysis and Definition
Word Part
Term
an/o
anorectal
-al = pertaining to
an = anus
rect/o = rectum
Pertaining to the anus and
rectum
perianal
peri- around
Pertaining to around the anus
appendectomy
append = appendix
-ectomy = surgical
removal
Surgical removal of the
appendix
appendicitis
-itis = inflammation
Inflammation of the appendix
append/o,
appendic/o
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Term Analysis
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Definition
Word Part
Term
bil/o
biliary
bil = bile
-ary = pertaining to
Pertaining to bile
bucc/o
buccal mucosa
bucc = cheek
-al = pertaining to
mucosa = mucous
membrane
Pertaining to the mucous
membrane of the cheek.
cec/o
cecopexy
cec = cecum
-pexy = surgical
fixation
Surgical fixation of the cecum
ileocecal
ile = ileum
-al = pertaining to
Pertaining to the ileum and
cecum
cheiloplasty
cheil = lips
-plasty = surgical
repair
Surgical repair of the lips
cheilosis
-osis = abnormal
condition
Abnormal condition of the lips
labial
-al = pertaining to
Pertaining to the lips
cholangi/o
cholangiogram
cholangi = bile duct
-gram = graphic
record
A record of the bile ducts
cholecyst/o
cholecystitis
chole = gallbladder
-itis = inflammation
Inflammation of the gall
bladder
cholecystectomy
-ectomy = surgical
removal
Surgical removal of the
gallbladder
colitis
col = colon
-itis = inflammation
Inflammation of the colon
colonoscopy
-scopy = process of
visually examining
Process of visually examining
the colon.
colostomy
-stomy = permanent
new opening
Creation of a permanent new
opening into the colon.
periodontist
peri = around
Specialist who deals with the
diseases around the teeth
periodontitis
-itis = inflammation
Inflammation of the area
around the teeth
cheil/o,
labi/o
col/o,
colon/o
dent/o,
odont/o
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Term Analysis
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Definition
Word Part
Term
duoden/o
duodenal
duoden =
duodenum
-al = pertaining to
Pertaining to the duodenum
enter/o
gastroenteritis
gastro = stomach
enter = small
intestine
-itis = inflammation
Inflammation of the stomach
and small intestine.
gastroenterology
-logy = study of
Study of the stomach and
small intestine
gastroenterologist
-logist = specialist
Specialist in the study of the
stomach and small intestine
esophageal
esophag =
esophagus
-al = pertaining to
Pertaining to the esophagus
esophagitis
-itis = inflammation
Inflammation of the esophagus
gastrectomy
gastr = stomach
-ectomy = surgical
removal
Surgical removal of the
stomach
gastrointestinal
-intestin = intestines
-al = pertaining to
Pertaining to the stomach and
intestines
nasogastric
tube
nas = nose
-ic = pertaining to
Pertaining to a tube that goes
from the nose into the stomach
gingiv/o
gingivitis
gingiv = gums
-itis = inflammation
Inflammation of the gums
gloss/o,
lingu/o
glossectomy
gloss = tongue
-ectomy = surgical
removal
Surgical removal of the tongue.
sublingual
lingu = tongue
sub = under
-al = pertaining to
Pertaining to under the tongue.
hepatitis
hepat = liver
-itis = inflammation
Inflammation of the liver
hepatocyte
-cyte = cell
Liver cell
hepatoma
-oma = tumor
Tumor of the liver
esophag/o
gastr/o
hepat/o
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Term Analysis
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Definition
Word Part
ile/o
jejun/o
lapar/o
lith/o
Term
Term Analysis
Definition
transhepatic
trans = across
-is = pertaining to
Pertaining to across the liver
ileostomy
ile = ileum
-stomy = permanent
new opening
Creation of a permanent new
opening into the ileum
ileotomy
-tomy = Surgical
incision
Surgical incision into the ileum
jejunal
jejun = jejunum
-al = pertaining to
Pertaining to the jejunum
gastrojejunostomy
gastro = stomach
jejun = jejunum
-omy = permanent
new opening
Creation of a permanent new
opening between the stomach
and jejunum
laparoscope
lapar = abdomen
-scope = instrument
to visually examine
Instrument used to examine
the abdomen
choledocholithiasis
choledoch =
common bile duct
-iasis = condition
lith = stone
Condition of stones in the
common bile duct
lithotripsy
tripsy = crushing
Crushing of stones
orex/i
anorexia
a(n) = no, lack of
orex = appetite
-ia = condition
Condition where there is a loss
of appetite
or/o
stomat/o
oral
or = mouth
-al = pertaining to
Pertaining to the mouth
stomatitis
stomat = mouth
-itis = inflammation
Inflammation of the mouth
pancreatogenic
pancreat =
pancreas
-genic = produced
by
Produced by the pancreas
pancreatitis
-itis = inflammation
Inflammation of the pancreas
pancreat/o
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Word Part
Term
Term Analysis
Definition
peritone/o
peritonitis
peritone=
peritoneum
-itis = inflammation
Inflammation of the peritoneum
retroperitoneal
retro = behind
-eal = pertaining to
Pertaining to behind the
peritoneum
pharyng/o
pharyngeal
pharyng = pharynx
-eal = pertaining to
Pertaining to the pharynx
proct/o,
proctoscopy
proct = rectum and
anus
-scopy = visual
examination using a
scope
Visual examination of the
rectum and anus
pylor/o
pylorospasm
pylor = pylorus
-spasm = sudden
involuntary
contraction
Sudden involuntary contraction
of the pylorus
pyloromyotomy
my = muscle
-tomy = Surgical
incision
rect = rectum
-stenosis =
narrowing
Surgical incision into the
muscle of the pylorus
rect/o
rectostenosis
sial/o
salivary
sial = saliva
-ary = pertaining to
Pertaining to the saliva
sialaden/o
sialadentitis
sialadent = salivary
gland
-itis = inflammation
Inflammation of the salivary
gland
sigmoid/o
sigmoidoscopy
sigmoid = sigmoid
colon
-scopy = visual
examination
Visual examination of the
sigmoid colon
viscer/o
visceroptosis
viscer = internal
organs
-ptosis = drooping,
sagging
Drooping of the internal organs
-grade
retrograde
-grade = to step, to
go
retro = backward
Backward flow of fluid
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Narrowing of the rectum
Word Part
Term
Term Analysis
Definition
-emesis
hyperemesis
hyper = excessive
-emesis = vomiting
Excessive vomiting
hematemesis
hemat = blood
Vomiting of blood
-phagia
aphagia
-phagia = eating,
swallowing
a = no, lack of
No eating
-plakia
dysphagia
leukoplakia
dys = difficult
-plakia = patches
leuk = white
Difficulty in eating
White patches on the mucous
membranes
-pepsia
dyspepsia
-pepsia = digestion
dys = difficult
Difficulty in digesting,
indigestion
endo-
endoscopy
endo = within
-scopy = visual
examination
Process of visually examining
the internal organs
Vocabulary Words
Absorption: The process whereby nutrient material is taken into the blood stream or
lymph.
Ascites:
An accumulation of serous fluid in the peritoneal cavity.
Cirrhosis:
A chronic degenerative liver disease characterized by changes in the
lobes; parenchymal cells and the lobules are infiltrated with fat.
Defecation: The evacuation of the material in the bowel.
Deglutition: The act or process of swallowing.
Diarrhea:
Frequent or watery stools
Emesis:
Vomiting
Esophageal reflux:
A return or backward flow of gastric contents into the esophagus.
Halitosis:
Bad breath
Lavage:
To wash out a cavity
Mastication: Chewing
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Melena:
Black feces caused by the action of intestinal juices on blood.
Abbreviations:
ac:
(ante cibum) before meals
BM:
Bowel movement
BS:
Bowel sounds
GI:
Gastrointestinal
NPO:
nothing by mouth
pc:
(post cibum) after meals
po:
By mouth
TPN:
Total parenteral nutrition
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